Valve for steam-pumps



(No Model.) 2' Sheets-Sheet 1..

E. A. MARSH.

VALVE FOB. STEAM PUMPS.

No. 394,656. Patented Dec. 18, 1888.

(No Model.)

` 2 Sheets-Sheet 2. E. A.' MARSH.

VALVE FOR STEAM PUMPS.

Patented Dec.l 18, 1888.

g1 o d l N A e P nj L L f 1; |l J@ i It l H w 'l 1l lf M I 'm l n will-H @@Mmaoo Juve/@bom mi, @5% AM 68%? N, PETERi Phuivumagnphnnwashington. UC,

UNITED STATES PATENT OFFICE.

EIION A. MARSH, OF BATTLE CREEK, MICHIGAN.

VALVE FOR STEAM-PUMPS.

SPECIFICATION forming part of Letters Patent No. 394,656, dated December18, 1888.

Application filed July 12, 1888. Serial No. 279,772. (No model.)

the same.

My invention relates to improvements in steam-pumps, a principal objectot' theinvention being to regulate the pressure of steam in thecylinder, so as to obtain isochronal movements ot' the pump andsteam-piston under varying' resistances, thus dispensing with the usualgovernor, in which the operation is always later than required foraffording pert'ect control of the machine.

To this end my invention consists, generally, of the combination of asteam-engine valve and steam-ports constructed and arranged, ashereinafter described, to admit, cut oit, or regulate the admission ofsteam to the cylinder, to increase or diminish the pressure thereinthrough the medium of, and to correspond with the varying resistance to,the movement of the piston.

The details of the invention will be hereinafter particularly described,and pointed out in the claims.

In the drawings, Figure l is a longitudinal vertical section through thesteam-chest and steam and water cylinders, showing the airchamber inelevation. Fig. 2 is a similar section through the exhaust and suctionchamber, showing the steam-chest in elevation; and Fig. 3 is a sectionaldetail.

A is the main casting, in which the cylinders and chambers are formed,and to which the appendages are attached.

A is the steam-cylinder, A" the water-cylinder, N the exhaust-chamber,and M the suction-chamber, all preferably formed within the main castingA, as clearly appears in the drawin Obviously these chambers may beformed of separate parts and then connected together without changingthe character ot' my invention.

B is the steam-chest, mounted on the enginecylinder in any usual orapproved way and provided with live-steam passages Gr G G" 1V",steam-ports F F, and enlarged end chambers, B B". The ports F F are ot'less capacity than the annular ports a and a and operate to restrict theincoming steam.

E is the live-steam pipe from the generator. The steam-chest is providedalso with a trip hole or passage in front of the plane of section ot'Fig. 1, (shown in dotted lines at 1),) leading from the live-steampassages E E to the steam-cylinder. It is also provided with trip-holesb b, leading from steam-cylinder to the valve-chambers B B, for apurpose hereinafter explained.

D D is the steam or actuating valve of the engine, closely iitting thecentral bore of the steam-chest. This valve is reduced near the ends andalong the middle, as shown, so as to admit steam through the annularports a a and to exhaust at a. The valve is also provided with enlargedheads D" D", which iit the bore of the chambers B B. The area of theinside of these heads is reduced by the area of the reduced portions D Dof the valve.

C C are the steam and water pistons, connected together and fitted totheir respective cylinders A and A. The steam-piston is provided with alongitudinal channel or passage, c, having lateral holes c c, leadingtherefrom, which alternately registerwith the trip-holes b b and b b.

J is a pin mounted in the main casting, projecting into a hole in thecylinder, to form a guide or stop to prevent the said cylinder fromrotating, and thus insure the correct registry of the holes c c with thetrip-holes at each stroke of the piston.

H H are the cylinder-heads; I I, the steamchest heads; T T, thecylinder-cocks; F, the air-cock; P, the water-suction pipe; P, thewater-discharge pipe; L, the atmosphere-exhaust pipe; R, the air-chamberto the pump;

O a three-wa Y valve or cock for makin@ communication fromexhaust-chamber N to atmosphere through L or from N to suctionchamber M;O, the valve-operating lever; Q and Q', pump-valves, and S a removablevalve-seat.

IOO

Suitable stops are provided on the main casting to limit the movement ofthe valvelever. y

The operation of my invention is as follows: The piston being in theposition shown in Fig. l and steam admitted from live-steam pipe E, itfirst passes from F. through passag'e b c b to enlarged chamber B, and,acting on the head D drives the valve to the left and opens the annularport a. Then this is done, steam passes through annular port a to theenlarged chamber B, and thence through port F and passage G to the maincylinder. The capacity of the port F being less than that of port aproduces a stricture on the inflowing steam,and the pressure on thesmaller inside surface of the head D becomes greater than against thelarger outer surface, and thus moves the valve to the right until itsufficiently restricts the annular port a to produce the proper relativepressures on the outside and inside of the valve-head and to move thepiston. lVhenv the piston Chas moved far enough to uncover the passageb, the pressure in the chamber will immediately rise and become uniformwith that in the main cylinder. This increased pressure in the outer endof chamber l5 now exerts itself upon the larger area of valve-head D anddrives the valve to the left and enlarges the annular induction-port a.As steam moves more rapidly than the piston, the pressure in thecylinder will be suddenly augmented, and this rise of pressure operatesstill further to enlarge the induction-port; but when the pressure ofsteam. in the cylinder becomes so great as to be out of proportion tothe resistance the piston will race or rapidly recede before thepreponderance of force and the pressure will become reduced by reason ofrapid expansion. This Areduction of pressure in the cylinder and outerend of the chamber B enables the incoming steam to again move the valveto the right until the forces on the two faces of the valve-head areneutralized. The valve thus automatically operated is the governor andregulator of the engine. The normal speed of the pump is fixed by therelative size of the ports a a and the ports F F', the speed beinggreater when the stricture-ports F F approach most nearly the capacityof the ports a a. The stricture-ports are made so as to bereduced orenlarged at will by screw cut-offs z e, or otherwise, as may be desired,so as to regulate the speed of the engine. The piston having moved tothe left, so that the openings c c register with the passages b li', acontinuous passage) c b', for live steam from the pipe E to the outerend of chamber B is made, and pressure on the outer surface of head Dmoves the valve to the right and reverses the current of steam. Theannulus a of the valve now couples the passage G G and exhaust takesplace from the right of the cylinder through- G G G to theexhaust-chamber N. The

piston is driven to the right until thepassage c is again registeredwith the passages b 1), when the movement is again reversed, and so on.Vhen the water plunger C moves from right to left, the air in thewatercylinder A is driven through the passage leading fromwater-cylinder to water-valve chamber, causing the water-valve Q toleave its seat and allow the air to escape either through pipe P orair-cock U. The valve then returns to its seat, and upon thereturn-stroke valve Q leaves its seat and air from suction-chamber M isadmitted. When the air is exhausted from chamber M and suction-pipe,water rises and fills the watercylinder, and the machine will be incomplete operation.

While the air is being exhausted the valve O should be turned to opencommunication between exhaust-chamber N and pipe L, to permit theexhaust-steam to pass to atmosphere. After the pump has taken water, thevalve O should be turned to the position shown in the drawings to divertthe exhauststeam to suction-chamber M, where it is condensed and impartsits heat to the water-an important matter when used as a feed-water.

Having now described my invention, I claiml. In combination, asteam-chest provided with suitable ports, chambers and restrictedpassages from the chamber to the cylinder, and an actuating-valve havingheads with faces of unequal area, whereby said valve is operated todiminish or increase the iiow of steam, and thereby regulate thepressure in the cylinder to correspond with the resistance to the pistonor work to be done, substantially as described.

2. In combination, a steam-chest having restricted portage fromvalve-chamber to cylinder and an automatic valve having heads with facesof unequal area operating to produce isochronism of the piston by equaland differential steam-pressure acting upon the unequal areas of theheads, the resistance of the piston serving to automatically regulatethe pressure in the cylinder to correspond with the work required,substantially as described. I

In combination, an automatic valve for steam-engines, a trip-passageleading from live-steam passage to the engine-cylinder, similar passagesleading from each end of said cylinder to the ends of the valve-chamber,and a longitudinal passage in the enginepiston, whereby the end passagesfrom cylinder to the ends of valve-chamber are alternatel-y coupled tothe passage from live-steam pipe, and the valve is reversed bylive-steam pressure, substantially as described.

4L. An automatic valve for steam-engines, provided with exteriorenlargements having faces of different areas, in combination withinduction-ports and restricting-ports, substantially as described.

5. The combination, witha steam-chest IOO IIO

having annular admission-ports and secondary restriction-ports, of@valve provided with heads having faces of unequal area, whereby theportage is restricted When the pressure in the engine is beyond thatrequired to do the i work, and said portage is increased when theVitnesses:

pressure is insufficient, substantially as del STEVEN S. HULBERT,scribed. i GEORGE W. MECHEM.

In testimony whereof I afx 'my signature in presence of two Witnesses.

ELON A. MARSH.

